<?php
/**
 * UnZip Class
 *
 * This class is based on a library I found at PHPClasses:
 * http://phpclasses.org/package/2495-PHP-Pack-and-unpack-files-packed-in-ZIP-archives.html
 *
 * The original library is a little rough around the edges so I
 * refactored it and added several additional methods -- Phil Sturgeon
 *
 * This class requires extension ZLib Enabled.
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Encryption
 * @author		Alexandre Tedeschi
 * @author		Phil Sturgeon
 * @author		Don Myers
 * @link		http://bitbucket.org/philsturgeon/codeigniter-unzip
 * @license
 * @version     1.0.0
 */
class Unzip {

    private $compressed_list = array();

    // List of files in the ZIP
    private $central_dir_list = array();

    // Central dir list... It's a kind of 'extra attributes' for a set of files
    private $end_of_central = array();

    // End of central dir, contains ZIP Comments
    private $info = array();
    private $error = array();
    private $_zip_file = '';
    private $_target_dir = FALSE;
    private $apply_chmod = 0777;
    private $fh;
    private $zip_signature = "\x50\x4b\x03\x04";

    // local file header signature
    private $dir_signature = "\x50\x4b\x01\x02";

    // central dir header signature
    private $central_signature_end = "\x50\x4b\x05\x06";

    // ignore these directories (useless meta data)
    private $_skip_dirs = array('__MACOSX');

    private $_allow_extensions = NULL; // What is allowed out of the zip

    // --------------------------------------------------------------------

    /**
     * Constructor
     *
     * @access    Public
     * @internal param $string
     * @return \Unzip
     */
    function __construct()
    {
        define('FILE_READ_MODE', 0644);
        define('FILE_WRITE_MODE', 0666);
        define('DIR_READ_MODE', 0755);
        define('DIR_WRITE_MODE', 0777);
    }

    // --------------------------------------------------------------------

    /**
     * re inizilize all variables
     * @access	Private
     * @param		none
     * @return	none
     */
    private function _reinit()
    {
        $this->compressed_list = array();
        $this->central_dir_list = array();
        $this->end_of_central = array();
        $this->info = array();
        $this->error = array();
    }

    /**
     * Unzip all files in archive.
     *
     * @access    Public
     * @param $zip_file
     * @param null $target_dir
     * @param bool $preserve_filepath
     * @internal param $none
     * @return    none
     */
    public function extract($zip_file, $target_dir = NULL, $preserve_filepath = TRUE)
    {
        $this->_reinit();
        $this->_zip_file = $zip_file;
        $this->_target_dir = $target_dir ? $target_dir : dirname($this->_zip_file);

        if ( ! $files = $this->_list_files())
        {
            $this->set_error('ZIP folder was empty.');
            return FALSE;
        }

        $file_locations = array();
        foreach ($files as $file => $trash)
        {
            $dirname = pathinfo($file, PATHINFO_DIRNAME);
            $extension = pathinfo($file, PATHINFO_EXTENSION);

            $folders = explode('/', $dirname);
            $out_dn = $this->_target_dir . '/' . $dirname;

            // Skip stuff in stupid folders
            if (in_array(current($folders), $this->_skip_dirs))
            {
                continue;
            }

            // Skip any files that are not allowed
            if (is_array($this->_allow_extensions) AND $extension AND ! in_array($extension, $this->_allow_extensions))
            {
                continue;
            }

            if ( ! is_dir($out_dn) AND $preserve_filepath)
            {
                $str = "";
                foreach ($folders as $folder)
                {
                    $str = $str ? $str . '/' . $folder : $folder;
                    if ( ! is_dir($this->_target_dir . '/' . $str))
                    {
                        $this->set_debug('Creating folder: ' . $this->_target_dir . '/' . $str);

                        if ( ! @mkdir($this->_target_dir . '/' . $str))
                        {
                            $this->set_error('Desitnation path is not writable.');
                            return FALSE;
                        }

                        // Apply chmod if configured to do so
                        $this->apply_chmod AND chmod($this->_target_dir . '/' . $str, $this->apply_chmod);
                    }
                }
            }

            if (substr($file, -1, 1) == '/') continue;

            $file_locations[] = $file_location = $this->_target_dir . '/' . ($preserve_filepath ? $file : basename($file));

            $this->_extract_file($file, $file_location);
        }

        $this->compressed_list = array();

        return $file_locations;
    }

    // --------------------------------------------------------------------

    /**
     * What extensions do we want out of this ZIP
     *
     * @access    Public
     * @param     none
     * @return    none
     */
    public function allow($ext = NULL)
    {
        $this->_allow_extensions = $ext;
    }

    // --------------------------------------------------------------------

    /**
     * Show error messages
     *
     * @access    public
     * @param string $open
     * @param string $close
     * @internal param $string
     * @return    string
     */
    public function error_string($open = '<p>', $close = '</p>')
    {
        return $open . implode($close . $open, $this->error) . $close;
    }

    // --------------------------------------------------------------------

    /**
     * Show debug messages
     *
     * @access    public
     * @param string $open
     * @param string $close
     * @internal param $string
     * @return    string
     */
    public function debug_string($open = '<p>', $close = '</p>')
    {
        return $open . implode($close . $open, $this->info) . $close;
    }

    // --------------------------------------------------------------------

    /**
     * Save errors
     *
     * @access    Private
     * @param    string
     * @return    none
     */
    function set_error($string)
    {
        $this->error[] = $string;
    }

    // --------------------------------------------------------------------

    /**
     * Save debug data
     *
     * @access    Private
     * @param    string
     * @return    none
     */
    function set_debug($string)
    {
        $this->info[] = $string;
    }

    // --------------------------------------------------------------------

    /**
     * List all files in archive.
     *
     * @access    Public
     * @param     boolean
     * @return    mixed
     */
    private function _list_files($stop_on_file = FALSE)
    {
        if (sizeof($this->compressed_list))
        {
            $this->set_debug('Returning already loaded file list.');
            return $this->compressed_list;
        }

        // Open file, and set file handler
        $fh = fopen($this->_zip_file, 'r');
        $this->fh = &$fh;

        if ( ! $fh)
        {
            $this->set_error('Failed to load file: ' . $this->_zip_file);
            return FALSE;
        }

        $this->set_debug('Loading list from "End of Central Dir" index list...');

        if ( ! $this->_load_file_list_by_eof($fh, $stop_on_file))
        {
            $this->set_debug('Failed! Trying to load list looking for signatures...');

            if ( ! $this->_load_files_by_signatures($fh, $stop_on_file))
            {
                $this->set_debug('Failed! Could not find any valid header.');
                $this->set_error('ZIP File is corrupted or empty');

                return FALSE;
            }
        }

        return $this->compressed_list;
    }

    // --------------------------------------------------------------------

    /**
     * Unzip file in archive.
     *
     * @access    Public
     * @param     string , boolean
     * @param bool $target_file_name
     * @return    Unziped file.
     */
    private function _extract_file($compressed_file_name, $target_file_name = FALSE)
    {
        if ( ! sizeof($this->compressed_list))
        {
            $this->set_debug('Trying to unzip before loading file list... Loading it!');
            $this->_list_files(FALSE, $compressed_file_name);
        }

        $fdetails = &$this->compressed_list[$compressed_file_name];

        if ( ! isset($this->compressed_list[$compressed_file_name]))
        {
            $this->set_error('File "<strong>$compressed_file_name</strong>" is not compressed in the zip.');
            return FALSE;
        }

        if (substr($compressed_file_name, -1) == '/')
        {
            $this->set_error('Trying to unzip a folder name "<strong>$compressed_file_name</strong>".');
            return FALSE;
        }

        if ( ! $fdetails['uncompressed_size'])
        {
            $this->set_debug('File "<strong>$compressed_file_name</strong>" is empty.');

            return $target_file_name ? file_put_contents($target_file_name, '') : '';
        }

        fseek($this->fh, $fdetails['contents_start_offset']);
        $ret = $this->_uncompress(
            fread($this->fh, $fdetails['compressed_size']),
            $fdetails['compression_method'],
            $fdetails['uncompressed_size'],
            $target_file_name
        );

        if ($this->apply_chmod AND $target_file_name)
        {
            chmod($target_file_name, FILE_READ_MODE);
        }

        return $ret;
    }

    // --------------------------------------------------------------------

    /**
     * Free the file resource.
     *
     * @access    Public
     * @param     none
     * @return    none
     */
    public function close()
    {
        // Free the file resource
        if ($this->fh)
        {
            fclose($this->fh);
        }
    }

    // --------------------------------------------------------------------

    /**
     * Free the file resource Automatic destroy.
     *
     * @access    Public
     * @param     none
     * @return    none
     */
    public function __destroy()
    {
        $this->close();
    }

    // --------------------------------------------------------------------

    /**
     * Uncompress file. And save it to the targetFile.
     *
     * @access    Private
     * @param $content
     * @param $mode
     * @param $uncompressed_size
     * @param bool $target_file_name
     * @internal param $Filecontent , int, int, boolean
     * @return    none
     */
    private function _uncompress($content, $mode, $uncompressed_size, $target_file_name = FALSE)
    {
        switch ($mode)
        {
            case 0:
                return $target_file_name ? file_put_contents($target_file_name, $content) : $content;
            case 1:
                $this->set_error('Shrunk mode is not supported... yet?');
                return FALSE;
            case 2:
            case 3:
            case 4:
            case 5:
                $this->set_error('Compression factor ' . ($mode - 1) . ' is not supported... yet?');
                return FALSE;
            case 6:
                $this->set_error('Implode is not supported... yet?');
                return FALSE;
            case 7:
                $this->set_error('Tokenizing compression algorithm is not supported... yet?');
                return FALSE;
            case 8:
                // Deflate
                return $target_file_name ?
                    file_put_contents($target_file_name, gzinflate($content, $uncompressed_size)) :
                    gzinflate($content, $uncompressed_size);
            case 9:
                $this->set_error('Enhanced Deflating is not supported... yet?');
                return FALSE;
            case 10:
                $this->set_error('PKWARE Date Compression Library Impoloding is not supported... yet?');
                return FALSE;
            case 12:
                // Bzip2
                return $target_file_name ?
                    file_put_contents($target_file_name, bzdecompress($content)) :
                    bzdecompress($content);
            case 18:
                $this->set_error('IBM TERSE is not supported... yet?');
                return FALSE;
            default:
                $this->set_error('Unknown uncompress method: $mode');
                return FALSE;
        }
    }

    private function _load_file_list_by_eof(&$fh, $stop_on_file = FALSE)
    {
        // Check if there's a valid Central Dir signature.
        // Let's consider a file comment smaller than 1024 characters...
        // Actually, it length can be 65536.. But we're not going to support it.

        for ($x = 0; $x < 1024; $x++)
        {
            fseek($fh, -22 - $x, SEEK_END);

            $signature = fread($fh, 4);

            if ($signature == $this->central_signature_end)
            {
                // If found EOF Central Dir
                $eodir['disk_number_this'] = unpack("v", fread($fh, 2)); // number of this disk
                $eodir['disk_number'] = unpack("v", fread($fh, 2)); // number of the disk with the start of the central directory
                $eodir['total_entries_this'] = unpack("v", fread($fh, 2)); // total number of entries in the central dir on this disk
                $eodir['total_entries'] = unpack("v", fread($fh, 2)); // total number of entries in
                $eodir['size_of_cd'] = unpack("V", fread($fh, 4)); // size of the central directory
                $eodir['offset_start_cd'] = unpack("V", fread($fh, 4)); // offset of start of central directory with respect to the starting disk number
                $zip_comment_lenght = unpack("v", fread($fh, 2)); // zipfile comment length
                $eodir['zipfile_comment'] = $zip_comment_lenght[1] ? fread($fh, $zip_comment_lenght[1]) : ''; // zipfile comment

                $this->end_of_central = array(
                    'disk_number_this' => $eodir['disk_number_this'][1],
                    'disk_number' => $eodir['disk_number'][1],
                    'total_entries_this' => $eodir['total_entries_this'][1],
                    'total_entries' => $eodir['total_entries'][1],
                    'size_of_cd' => $eodir['size_of_cd'][1],
                    'offset_start_cd' => $eodir['offset_start_cd'][1],
                    'zipfile_comment' => $eodir['zipfile_comment'],
                );

                // Then, load file list
                fseek($fh, $this->end_of_central['offset_start_cd']);
                $signature = fread($fh, 4);

                while ($signature == $this->dir_signature)
                {
                    $dir['version_madeby'] = unpack("v", fread($fh, 2)); // version made by
                    $dir['version_needed'] = unpack("v", fread($fh, 2)); // version needed to extract
                    $dir['general_bit_flag'] = unpack("v", fread($fh, 2)); // general purpose bit flag
                    $dir['compression_method'] = unpack("v", fread($fh, 2)); // compression method
                    $dir['lastmod_time'] = unpack("v", fread($fh, 2)); // last mod file time
                    $dir['lastmod_date'] = unpack("v", fread($fh, 2)); // last mod file date
                    $dir['crc-32'] = fread($fh, 4);			  // crc-32
                    $dir['compressed_size'] = unpack("V", fread($fh, 4)); // compressed size
                    $dir['uncompressed_size'] = unpack("V", fread($fh, 4)); // uncompressed size
                    $zip_file_length = unpack("v", fread($fh, 2)); // filename length
                    $extra_field_length = unpack("v", fread($fh, 2)); // extra field length
                    $fileCommentLength = unpack("v", fread($fh, 2)); // file comment length
                    $dir['disk_number_start'] = unpack("v", fread($fh, 2)); // disk number start
                    $dir['internal_attributes'] = unpack("v", fread($fh, 2)); // internal file attributes-byte1
                    $dir['external_attributes1'] = unpack("v", fread($fh, 2)); // external file attributes-byte2
                    $dir['external_attributes2'] = unpack("v", fread($fh, 2)); // external file attributes
                    $dir['relative_offset'] = unpack("V", fread($fh, 4)); // relative offset of local header
                    $dir['file_name'] = fread($fh, $zip_file_length[1]);							 // filename
                    $dir['extra_field'] = $extra_field_length[1] ? fread($fh, $extra_field_length[1]) : ''; // extra field
                    $dir['file_comment'] = $fileCommentLength[1] ? fread($fh, $fileCommentLength[1]) : ''; // file comment

                    // Convert the date and time, from MS-DOS format to UNIX Timestamp
                    $binary_mod_date = str_pad(decbin($dir['lastmod_date'][1]), 16, '0', STR_PAD_LEFT);
                    $binary_mod_time = str_pad(decbin($dir['lastmod_time'][1]), 16, '0', STR_PAD_LEFT);
                    $last_mod_year = bindec(substr($binary_mod_date, 0, 7)) + 1980;
                    $last_mod_month = bindec(substr($binary_mod_date, 7, 4));
                    $last_mod_day = bindec(substr($binary_mod_date, 11, 5));
                    $last_mod_hour = bindec(substr($binary_mod_time, 0, 5));
                    $last_mod_minute = bindec(substr($binary_mod_time, 5, 6));
                    $last_mod_second = bindec(substr($binary_mod_time, 11, 5));

                    $this->central_dir_list[$dir['file_name']] = array(
                        'version_madeby' => $dir['version_madeby'][1],
                        'version_needed' => $dir['version_needed'][1],
                        'general_bit_flag' => str_pad(decbin($dir['general_bit_flag'][1]), 8, '0', STR_PAD_LEFT),
                        'compression_method' => $dir['compression_method'][1],
                        'lastmod_datetime' => mktime($last_mod_hour, $last_mod_minute, $last_mod_second, $last_mod_month, $last_mod_day, $last_mod_year),
                        'crc-32' => str_pad(dechex(ord($dir['crc-32'][3])), 2, '0', STR_PAD_LEFT) .
                            str_pad(dechex(ord($dir['crc-32'][2])), 2, '0', STR_PAD_LEFT) .
                            str_pad(dechex(ord($dir['crc-32'][1])), 2, '0', STR_PAD_LEFT) .
                            str_pad(dechex(ord($dir['crc-32'][0])), 2, '0', STR_PAD_LEFT),
                        'compressed_size' => $dir['compressed_size'][1],
                        'uncompressed_size' => $dir['uncompressed_size'][1],
                        'disk_number_start' => $dir['disk_number_start'][1],
                        'internal_attributes' => $dir['internal_attributes'][1],
                        'external_attributes1' => $dir['external_attributes1'][1],
                        'external_attributes2' => $dir['external_attributes2'][1],
                        'relative_offset' => $dir['relative_offset'][1],
                        'file_name' => $dir['file_name'],
                        'extra_field' => $dir['extra_field'],
                        'file_comment' => $dir['file_comment'],
                    );

                    $signature = fread($fh, 4);
                }

                // If loaded centralDirs, then try to identify the offsetPosition of the compressed data.
                if ($this->central_dir_list)
                {
                    foreach ($this->central_dir_list as $filename => $details)
                    {
                        $i = $this->_get_file_header($fh, $details['relative_offset']);

                        $this->compressed_list[$filename]['file_name'] = $filename;
                        $this->compressed_list[$filename]['compression_method'] = $details['compression_method'];
                        $this->compressed_list[$filename]['version_needed'] = $details['version_needed'];
                        $this->compressed_list[$filename]['lastmod_datetime'] = $details['lastmod_datetime'];
                        $this->compressed_list[$filename]['crc-32'] = $details['crc-32'];
                        $this->compressed_list[$filename]['compressed_size'] = $details['compressed_size'];
                        $this->compressed_list[$filename]['uncompressed_size'] = $details['uncompressed_size'];
                        $this->compressed_list[$filename]['lastmod_datetime'] = $details['lastmod_datetime'];
                        $this->compressed_list[$filename]['extra_field'] = $i['extra_field'];
                        $this->compressed_list[$filename]['contents_start_offset'] = $i['contents_start_offset'];

                        if (strtolower($stop_on_file) == strtolower($filename))
                        {
                            break;
                        }
                    }
                }

                return TRUE;
            }
        }
        return FALSE;
    }

    private function _load_files_by_signatures(&$fh, $stop_on_file = FALSE)
    {
        fseek($fh, 0);

        $return = FALSE;
        for (;;)
        {
            $details = $this->_get_file_header($fh);

            if ( ! $details)
            {
                $this->set_debug('Invalid signature. Trying to verify if is old style Data Descriptor...');
                fseek($fh, 12 - 4, SEEK_CUR); // 12: Data descriptor - 4: Signature (that will be read again)
                $details = $this->_get_file_header($fh);
            }

            if ( ! $details)
            {
                $this->set_debug('Still invalid signature. Probably reached the end of the file.');
                break;
            }

            $filename = $details['file_name'];
            $this->compressed_list[$filename] = $details;
            $return = true;

            if (strtolower($stop_on_file) == strtolower($filename))
            {
                break;
            }
        }

        return $return;
    }

    private function _get_file_header(&$fh, $start_offset = FALSE)
    {
        if ($start_offset !== FALSE)
        {
            fseek($fh, $start_offset);
        }

        $signature = fread($fh, 4);

        if ($signature == $this->zip_signature)
        {
            // Get information about the zipped file
            $file['version_needed'] = unpack("v", fread($fh, 2)); // version needed to extract
            $file['general_bit_flag'] = unpack("v", fread($fh, 2)); // general purpose bit flag
            $file['compression_method'] = unpack("v", fread($fh, 2)); // compression method
            $file['lastmod_time'] = unpack("v", fread($fh, 2)); // last mod file time
            $file['lastmod_date'] = unpack("v", fread($fh, 2)); // last mod file date
            $file['crc-32'] = fread($fh, 4);			  // crc-32
            $file['compressed_size'] = unpack("V", fread($fh, 4)); // compressed size
            $file['uncompressed_size'] = unpack("V", fread($fh, 4)); // uncompressed size
            $zip_file_length = unpack("v", fread($fh, 2)); // filename length
            $extra_field_length = unpack("v", fread($fh, 2)); // extra field length
            $file['file_name'] = fread($fh, $zip_file_length[1]); // filename
            $file['extra_field'] = $extra_field_length[1] ? fread($fh, $extra_field_length[1]) : ''; // extra field
            $file['contents_start_offset'] = ftell($fh);

            // Bypass the whole compressed contents, and look for the next file
            fseek($fh, $file['compressed_size'][1], SEEK_CUR);

            // Convert the date and time, from MS-DOS format to UNIX Timestamp
            $binary_mod_date = str_pad(decbin($file['lastmod_date'][1]), 16, '0', STR_PAD_LEFT);
            $binary_mod_time = str_pad(decbin($file['lastmod_time'][1]), 16, '0', STR_PAD_LEFT);

            $last_mod_year = bindec(substr($binary_mod_date, 0, 7)) + 1980;
            $last_mod_month = bindec(substr($binary_mod_date, 7, 4));
            $last_mod_day = bindec(substr($binary_mod_date, 11, 5));
            $last_mod_hour = bindec(substr($binary_mod_time, 0, 5));
            $last_mod_minute = bindec(substr($binary_mod_time, 5, 6));
            $last_mod_second = bindec(substr($binary_mod_time, 11, 5));

            // Mount file table
            $i = array(
                'file_name' => $file['file_name'],
                'compression_method' => $file['compression_method'][1],
                'version_needed' => $file['version_needed'][1],
                'lastmod_datetime' => mktime($last_mod_hour, $last_mod_minute, $last_mod_second, $last_mod_month, $last_mod_day, $last_mod_year),
                'crc-32' => str_pad(dechex(ord($file['crc-32'][3])), 2, '0', STR_PAD_LEFT) .
                    str_pad(dechex(ord($file['crc-32'][2])), 2, '0', STR_PAD_LEFT) .
                    str_pad(dechex(ord($file['crc-32'][1])), 2, '0', STR_PAD_LEFT) .
                    str_pad(dechex(ord($file['crc-32'][0])), 2, '0', STR_PAD_LEFT),
                'compressed_size' => $file['compressed_size'][1],
                'uncompressed_size' => $file['uncompressed_size'][1],
                'extra_field' => $file['extra_field'],
                'general_bit_flag' => str_pad(decbin($file['general_bit_flag'][1]), 8, '0', STR_PAD_LEFT),
                'contents_start_offset' => $file['contents_start_offset']
            );

            return $i;
        }

        return FALSE;
    }
}

/* End of file Unzip.php */
/* Location: ./system/libraries/Unzip.php */